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Updated: Jul 13, 2026
08:15
Synthesis of Nine-atom Deltahedral Zintl Ions of Germanium and their Functionalization with Organic Groups
Published on: February 11, 2012
Dicalcium heptagermanate Ca(2)Ge(7)O(16) revised.
Günther J Redhammer1, Georg Roth, Georg Amthauer
1Department of Materials Engineering and Physics, Division of Mineralogy, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. guenther.redhammer@aon.at
Summary
The crystal structure of dicalcium heptagermanate was redetermined in a new tetragonal space group. This reveals an alternating arrangement of germanium tetrahedra and octahedra, forming a unique framework.
Area of Science:
- Solid-state chemistry
- Crystallography
- Materials science
Background:
- Previous structural descriptions of dicalcium heptagermanate were based on an orthorhombic space group.
- Accurate structural data is crucial for understanding material properties.
Purpose of the Study:
- To redetermine the crystal structure of dicalcium heptagermanate.
- To clarify its crystallographic details and structural arrangement.
Main Methods:
- Single-crystal X-ray diffraction.
- Crystallographic refinement.
- Space group determination.
Main Results:
- The structure was redetermined in the tetragonal space group P(overline4)b2.
- Dicalcium heptagermanate features three distinct germanium (Ge) positions and one calcium (Ca) position.
- The framework consists of alternating sheets of Ge tetrahedra and Ge octahedra, with Ca sites, arranged in an ABABA... sequence along the c-axis.
Conclusions:
- The redetermined tetragonal structure provides a more accurate representation of dicalcium heptagermanate.
- The unique framework with channel-like structures offers potential for novel material applications.
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